I have a Bresser Advance ICD Trinocular Microscope 160x and didn’t break the bank at £350. It has both lighting from below and above and with a combination of lenses I can go from 10x to 160x – http://www.bresser.de/en/Microscopes-Magnifiers/Microscopes/BRESSER-Advance-ICD-10x-160x-Stereo-Microscope.html. It also has a very useful third port for my camera. Although I had to buy the adapter for my Sony NEX7 at an additional cost of $99 all the way from the USA with an additional postage cost of $16 – Ebay seller imaging_apparatus.
The difficulty I have is that some of the people in the Gemology and Jewelry trade do not think twice about spending £500 on a piece of equipment because they will be charging clients for using them for years to come. Markup in the Gem field is so high that a the first ten stones they move will pay for the equipment outright. Amateurs, like myself, may not get the best equipment but can live with that knowing that Christmas will come every year and build up stuff slowly or survive without.
That said I would love to buy all my equipment from GEM A but price restricts. So anyone want to donate some old GEM A equipment to a poor retired armature gemologist feel free to contact me… 😉